Fix dry-run of haproxy migration path

Author: Julien Girardin

tests/features/haproxy.feature

@@ -35,6 +35,8 @@ Feature: Haproxy
         When With those group_vars on group all:
             apiserver_proxy_use_docker: false
         When I reset tasks counters
+        When I dry-run the playbooks 00_apiserver_proxy.yml
+        When I reset tasks counters
         When I run the playbooks 00_apiserver_proxy.yml
                                  01_site.yml
         Then I should have a working cluster

tests/helpers/ansible.py

@@ -1,5 +1,6 @@
 import itertools
 import os
+import re
 
 import ansible_runner
 
@@ -56,5 +57,6 @@ def run_ansible_playbook(
 
 def assert_ansible_error(run):
     assert run.status == "successful"
+    assert len(re.findall(r"fatal: [.*]: FAILED! =>.*", run.stdout.read())) == 0
     for host_failed, number_failed in run.stats.get("failures", {}).items():
         assert number_failed == 0